Iranian First Vice President Mohammad Mokhber (R) attends the emergency meeting, held by government council, following the death of Iranian President Ebrahim Raisi and other senior government officials in a helicopter crash in Tehran, Iran, May 20, 2024. IRANIAN PRESIDENCY/HANDOUT/ANADOLU/GETTY

Iran President Ebrahim Raisi was killed in a Sunday helicopter crash along with the Islamic republic's foreign minister and others, the country's state media confirmed Monday morning. Raisi, a hardline Islamic cleric who had been tipped as a possible successor to Iran's Supreme Leader Ayatollah Ali Khamenei, was 63.

Under the Islamic republic's governing system, Raisi, like all presidents who served before him since the 1979 Islamic Revolution that brought the ayatollahs to power, is not the country's ultimate decision-maker. All government officials, along with the military and all law enforcement agencies, answer ultimately to Khamenei, who at 85 has ruled over the country since 1989 as its second supreme leader.

Given that power structure, CBS News' Seyed Bathaei in Tehran said it was unlikely that Raisi's death would spark any political crisis, and the supreme leader was quick to assure his country that government business would continue unphased.

Who replaces Iran's President Raisi, and how?
As per Iran's constitution, First Vice President Mohammad Mokhber became the country's acting president on Monday, after his formal appointment by Ayatollah Khamenei. State media said Mokhber had already started receiving calls from officials and foreign governments before Khamenei announced his interim role.

The Iranian cabinet issued a statement after convening Monday pledging to follow Raisi's path and adding that, "with the help of God and the people, there will be no problem with management of the country."

The cabinet said the "hard-working president" had been "martyred" and vowed to keep the government running "without the slightest disruption."

Mokhber quickly appointed Ali Bagheri Kani, Iran's nuclear negotiator, as Foreign Ministry caretaker, cabinet spokesman Ali Bahadori Jahromi was quoted as saying.

What happens next?
The constitution calls for, and Khamenei reaffirmed on Monday, that the next step is for national elections to be held to pick a new president. That has to happen within 50 days. No date had been set by late Monday in Iran.

As acting president, Mokhber is tasked with organizing the unscheduled election to choose Raisi's formal successor.

Raisi won Iran's last presidential election in 2021 — a vote that saw the lowest turnout in the Islamic republic's history and which was dismissed as a highly undemocratic political exercise by the U.S. and other Western nations.

Iran's ruling clerics barred all opposition-minded candidates from running in the 2021 vote, and political speech is highly limited in the country.